There currently exists a number of lifting appliances more particularly designed to lift stationary airplanes. The lifting appliances or lifts usually comprise at least a few upright columns carrying therebetween a horizontally extending aircraft support platform, the platform being vertically movable by means of a lifting device for displacement between a lower limit position, engaging ground, and an upper limit position, in which the platform remains continuously above ground. These lifting appliances, mainly for use with large airplanes, use a concrete platform actuated by means of hydraulic devices in order to provide clearance in wing area, and thus, lay large airplanes side by side in a restricted area, so that their vertically offset respective wings clear one another. All those systems involve either a powerful engine, or are very expensive due to complex components: see U.S. Pat. No. 3,489,297 issued 13 Jan. 1970 to the J.E. Greiner Company.
In other systems, a lift truck is required in order to lift an aircraft supporting pallet over a permanently raised platform forming part of a ground standing frame: see U.S. Pat. No. 3,756,419 issued 4 Sep. 1973 to Charles DEAN.
U.S. Pat. No. 2,843,222 issued 15 Jul. 1958 to the Swiss Julio VILLARS, discloses a lifting assembly for lifting automobiles. This lifting assembly includes a single column rigidly mounted to the ground in upright condition by a base plate. The upright column is made of two cross-sectionally H-shape beams, mounted edgewisely to one another, wherein a closed upright channel of quadrangular cross-section is formed. A sleeve member is slidingly carried by the upright column, being movable lengthwisely thereof via integral rollers under bias from a vertical actuating screw. The actuating screw is energized by an electric motor mounted at the top end of the upright column. A pair of parallel spaced support arms are carried integrally by the hollow slider block, wherein by engaging the underside of an automobile frame, these support arms may vertically displace the automobile upon energizing the electric motor.
In one embodiment of the Villars patent, a Y-shape support member is mounted transversely of the main pair of parallel support legs, with a triplet of bearing surface plates at the ends of the three respective legs of the Y. In another variant, the upright column is carried by a carriage and the lifting member is a platform, wherein the lifting device is transportable.
Due to its design, the Villars lifting device is solely directed to road-going vehicles, and particularly automobiles. Such lifting devices usually require a relatively large power output to lift the loads. Moreover, the configuration of the support arms of the Villars lifting device is also a limiting factor as to its adaptability to alternate type of vehicles.